In the visible light spectrum, blue light is a high energy visible light having a short wavelength. Blue light is more scattered in the atmosphere than other wavelengths of the visible light. For example, a clear sky appears blue to human eyes. In a modern society, blue light is also emitted from many natural and artificial light sources such as a display apparatus, an energy-saving light bulb, LEDs, an incandescent light bulb, and sunlight. Due to its high energy level, blue light can easily penetrate lens of the eye and reach the retina. Moreover, blue light has a cumulative effect on the retina. Human eye's self-defense mechanism becomes less efficient over the years under the blue light exposure. Exposure to high intensity blue light over an extended period of time can accelerate oxidation process in macular area of the eye, causing substantial damages in the eye.